It’s the first agricultural system of its kind in the world and uses no soil, pesticides, fossil fuels or groundwater. As the demand for fresh water and energy continues to rise, this might be the face of farming in the future.

An international team of scientists have spent the last six years fine-tuning the design – first with a pilot greenhouse built in 2010; then with a commercial-scale facility that began construction in 2014 and was officially launched today.

Seawater is piped 2 kilometres from the Spencer Gulf to Sundrop Farm – the 20-hectare site in the Port Augusta area that was dry. A solar-powered desalination plant removes the salt, creating fresh water to irrigate 180,000 tomato plants inside the greenhouse.

Dry conditions and scorching summer temperatures make the area unsuitable for conventional farming, but the greenhouse is lined with seawater-soaked cardboard to keep the plants cool enough to remain healthy. In winter, solar heating keeps the greenhouse warm.

There’s no demand for pesticides as the atmosphere sterilises and cleans, and plants grow in coconut husks rather than land.

The farm’s 23,000 generates solar power mirrors that reflect sun towards a 115-metre high receiver tower. On a bright day, up to 39 megawatts of energy can be generated the desalination plant and provide the greenhouse’s electricity needs.

Tomatoes created by the greenhouse have began being sold in Australian supermarkets.

Future prognosis

Potential solar energy deficits in winter mean the greenhouse must be hooked up to the power system for backup, but slow progress to the layout will remove any reliance on fossil fuels, says Sundrop Farm CEO Philipp Saumweber.

The $200 million infrastructure makes the seawater greenhouse expensive to set up than conventional greenhouses, but the price will pay off long term, says Saumweber. Standard greenhouses are higher priced to run yearly due to the price of fossil fuels, he says.

Sundrop is currently intending to establish similar sustainable greenhouses in the US and Portugal, and another in Australia. Other businesses are also examining pilot seawater greenhouses in desert regions of the United Arab Emirates, Qatar and Oman.

These shut production systems are quite intelligent,” says Robert Park at the University of Sydney, Australia. “I consider that systems using sustainable energy sources will become better and better and grow in the foreseeable future, giving more of some of our foods.”

Yet, Paul Kristiansen at the University of New England, Australia, questions the demand for energy-intensive tomato farming in a desert, when there are perfect growing states in other areas of Australia.

“It’s a bit like smashing a garlic clove with a sledgehammer,” he says. “We don’t have difficulties growing tomatoes in Australia.”

However, the technology may become useful later on if climate change causes drought in once-rich areas, Kristiansen says. “Then it is going to be great to have back-up plans.”